alibi

noun | al·i·bi

1. : a defense of having been somewhere other than at the scene of a crime at the time the crime was committed; also : the fact or state of having been elsewhere at the time a crime was committed : the fact or state of having been elsewhere at the time a crime was committed

   Note: Federal Rule of Criminal Procedure 12.1 requires the defendant to provide notice upon written demand of an intention to offer a defense of alibi. The prosecution must provide to the defendant the names of witnesses that will be used to rebut it.